The data base presently available on microbial ecology (comprising data accumulated from ten years of taxonomic and ecological studies of a wide variety of niches and habitats) are being encoded in a standardized format established by Rogosa, Krichevsky and Colwell (1971) and transferred to a centralized data storage center. Data collection will be continued but with entry of new data via the standardized format to the central data storage facility, permitting testing of programs to be written for data entry, storage and processing. The data will serve as a model for developing on-line identification of microorganisms with dialogue between the investigator and the central data bank. New programs have been written, using FORTRAN, and present programs are being modified to improve efficiency and availability. The research is serving as a pilot study for the establishment of a national data bank, providing taxonomic and ecological analyses of the oral microflora. Mechanisms for recording and handling data for microorganisms in the oral cavity, in healthy and diseased subjects, permit analyses for elucidation of organisms and their interactions as involved in caries formation and/or periodontal disease.